Flock is a very short or pulverized fiber that can be used to, among other things, form a velvety pattern on cloth or paper, or a covering on metal or plastic. Flock is made from any number of known fibers including natural fibers, such as cotton and wool, as well as from wet or melt spun fibers, such as fluorocarbon polymer (“fluoropolymer”) fiber and carbon fiber. Fluoropolymer fiber flock is used as a friction modifier in many different end uses including electrical components, chemical processing equipment and in coatings for cooking utensils, bushings, bearings, pipes and gaskets. When used as a friction modifier in industrial applications, such as bearings, fluoropolymer fiber flock is typically prepared from a continuous fluoropolymer filament yarn chopped into very short flock; this flock is then mixed with a resin and molded into articles or parts. Carbon fiber flock, on the other hand, is generally used to reinforce materials like epoxy resins and other thermosetting materials. Carbon fiber reinforced composites are very strong for their weight and are often stronger than steel but lighter. When used in these applications, carbon fiber is typically prepared by melt-spinning or solution spinning to produce a precursor fiber which is extruded through a multi-hole spinneret resulting in a multifilament carbon fiber yarn. The yarn is then cut into very short flock and can be mixed with an epoxy resin or made into carbon fiber paper. Carbon fiber reinforced composites can be used to replace metals in many uses, from parts for airplanes and the space shuttle to tennis rackets and golf clubs.
When flock is derived from fluoropolymer yarn or carbon fiber yarn, as described above, it is well known that the individual filaments of the flock tend to stick together forming multifilament bundles of flock fibers, rather than individual flock fibers. With regard to fluoropolymer fibers, sticking typically occurs between adjacent filaments and is caused by sintering the fibers, which results in the fluoropolymer particles in adjacent filaments binding together. As a result, when used in different applications, the full benefits of including the flock are not realized, since the flock does not distribute evenly across or through an article and since the multifilament bundles do not present their full potential surface area on or within the article. However, by dispersing a portion the multifilament bundles of a flock into single-filament fibers, the flock can be more evenly distributed across or through an article, which has the effect of increasing the surface area of the flock over the surface area of the multifilament bundles. This way, the benefits derivable from flock are improved.